Sergio Perez led a Red Bull one-two as both Mercedes' finished outside the top 10 in Practice 2 at the Azerbaijan Grand Prix.
As drivers completed their first lower fuel runs of the weekend, the Mexican posted a 1m42.115s to lead teammate Max Verstappen by a tenth of a second.
The Dutchman though was clearly unhappy with the balance of his car, complaining of no grip at the front.
Ferrari also remains in the mix with Carlos Sainz 0.027s behind Verstappen in third and Charles Leclerc fourth, despite hitting the barrier at Turn 15 and dislodging his front wing.
The moment Leclerc found the Baku barrier 💥
— Formula 1 (@F1) June 4, 2021
He managed to recover from the incident and finished FP2 in P4 💪#AzerbaijanGP 🇦🇿 #F1 pic.twitter.com/5XQZSKvTUV
The other story though was at Mercedes where Lewis Hamilton was 11th and Valtteri Bottas 16th.
Tyre warm-up and an apparent lack of top speed were the main issues resulting in the pair being one and two seconds off the pace respectively.
Race pace did look more competitive on the long runs, but there's certainly a lot of work to do if the Brackley-based team want to be in the fight in qualifying.
Ahead, Pierre Gasly was fifth, while Fernando Alonso benefited from a huge tow on the main straight, crossing the speed trap some 11kph faster than anyone else en route to sixth.
It was a similar story for Antonio Giovinazzi in seventh. Lando Norris was the only Mercedes-powered car in the top 10 in eighth, ahead of Esteban Ocon and Yuki Tsunoda, despite more trips down the escape road.
Daniel Ricciardo was 13th in the second McLaren, with the two Aston Martins ahead of Bottas in 16th.
George Russell was 17th, as Nikita Mazepin led Haas teammate Mick Schumacher, who only managed 12 laps due to reliability issues.
Earlier in the session, Nicholas Latifi had caused the first red flag when his Williams stopped on the exit of Turn 15 shortly after reversing out of the escape road.
A fascinating final result raises the prospect of a very interesting weekend to come with Mercedes appearing in genuine trouble, while Verstappen's main competition might just be his teammate...
Full results from Practice 2 can be seen below:
